Physical Properties of AZ91D Measured Using the Draining Crucible Method: Effect of SF6

The draining crucible (DC) technique was used for measurements on AZ91D under Ar and SF6. The DC technique is a new method developed to simultaneously measure the physical properties of fluids, the density, surface tension, and viscosity. Based on the relationship between the height of a metal in a crucible and the outgoing flow rate, a multi-variable regression is used to calculate the values of these fluid properties. Experiments performed with AZ91D at temperatures from 923 K to 1173 K indicate that under argon, the surface tension (N . m(-1)) and density (kg . m(-3)) are [0.63 - 2.13 x 10(-4)(T - T-L)] and [1656 - 0.158(T - T-L)], respectively. The viscosity (Pa . s) has been determined to be [1.455 x 10(-3) - 1.209 x 10(-5)(T - T-L)] over the temperature range from 921 K to 967 K superheat. Above 967 K, the viscosity of the alloy under argon seems to be constant at (2.66 x 10(-4) +/- 8.67 x 10(-5)) Pa . s. SF6 reduces the surface tension of AZ91D.